Install a Python package into a different directory using pip?

Question

I know the obvious answer is to use virtualenv and virtualenvwrapper, but for various reasons I can\'t/don\'t want to do that.

So how do I modify the command

Answer 1

Instead of the --target option or the --install-options option, I have found that the following works well (from discussion on a bug regarding this very thing at https://github.com/pypa/pip/issues/446):

PYTHONUSERBASE=/path/to/install/to pip install --user

(Or set the PYTHONUSERBASE directory in your environment before running the command, using export PYTHONUSERBASE=/path/to/install/to)

This uses the very useful --user option but tells it to make the bin, lib, share and other directories you'd expect under a custom prefix rather than $HOME/.local.

Then you can add this to your PATH, PYTHONPATH and other variables as you would a normal installation directory.

Note that you may also need to specify the --upgrade and --ignore-installed options if any packages upon which this depends require newer versions to be installed in the PYTHONUSERBASE directory, to override the system-provided versions.

A full example:

PYTHONUSERBASE=/opt/mysterypackage-1.0/python-deps pip install --user --upgrade numpy scipy

..to install the scipy and numpy package most recent versions into a directory which you can then include in your PYTHONPATH like so (using bash and for python 2.6 on CentOS 6 for this example):

export PYTHONPATH=/opt/mysterypackage-1.0/python-deps/lib64/python2.6/site-packages:$PYTHONPATH
export PATH=/opt/mysterypackage-1.0/python-deps/bin:$PATH

Using virtualenv is still a better and neater solution!

Answer 2

I suggest to follow the documentation and create ~/.pip/pip.conf file. Note in the documentation there are missing specified header directory, which leads to following error:

error: install-base or install-platbase supplied, but installation scheme is incomplete

The full working content of conf file is:

[install]
install-base=$HOME
install-purelib=python/lib
install-platlib=python/lib.$PLAT
install-scripts=python/scripts
install-headers=python/include
install-data=python/data

Unfortunatelly I can install, but when try to uninstall pip tells me there is no such package for uninstallation process.... so something is still wrong but the package goes to its predefined location.

Answer 3

The --target switch is the thing you're looking for:

pip install --target=d:\somewhere\other\than\the\default package_name

But you still need to add d:\somewhere\other\than\the\default to PYTHONPATH to actually use them from that location.

-t, --target <dir>
Install packages into <dir>. By default this will not replace existing files/folders in <dir>.
Use --upgrade to replace existing packages in <dir> with new versions.

---

Upgrade pip if target switch is not available:

On Linux or OS X:

pip install -U pip

On Windows (this works around an issue):

python -m pip install -U pip

Answer 4

If you are using brew with python, unfortunately, pip/pip3 ships with very limited options. You do not have --install-option, --target, --user options as mentioned above.

Note on pip install --user
The normal pip install --user is disabled for brewed Python. This is because of a bug in distutils, because Homebrew writes a distutils.cfg which sets the package prefix. A possible workaround (which puts executable scripts in ~/Library/Python/./bin) is: python -m pip install --user --install-option="--prefix=" <package-name>

You might find this line very cumbersome. I suggest use pyenv for management. If you are using

brew upgrade python python3

Ironically you are actually downgrade pip functionality.

(I post this answer, simply because pip in my mac osx does not have --target option, and I have spent hours fixing it)